Grand Canyon: 
The Mile Deep Time Machine

Begun more than 2 billion years ago, it has eroded over a mile deep by the Colorado River in the last few million years

Map of Eastern Grand Canyon	Key to map
		Slumps landslides and rockfalls
		Travertine Deposits
		Kaibob Limestone
		Toroweap Formation
		Coconino Sandstone
		Esplanade Sandstone
		Westcogame Monokocho and Watahomigi
		Redwall limestone
		Moav Limestone
		Bright Angel Shale
		Tapeats Sandstone
Vertical Section		Kwogunt Formation
		Goleros Formation
		Cardenas Lava
		Dox Sandstone
		Hakatai Shale
		Granite to Grandodiorite
		Grandodiorite to Quartz Diorite
		Predominately Diabase Intrusives
		Predominately Schist
		Predominately Amphibolite

The Grand Canyon has been shaped by the passage of time and the ravages of nature. The region was at times covered by seas, rivers have cut deep gorges through surface strata, and earthquakes have bent, twisted, dropped and folded the land. Volcanic eruptions have spewed lava and ash and the land suffered through innumerable droughts. Fortunately, these forces occurred over the last four billion years. Had they all occurred at the same time, the area surely would have been hell on earth. 

There is no better place to study the formation of the earth than at the Grand Canyon. From the Canyon's rims, visitors may gaze down through as much as 6250 feet, [or 1.18 miles (1 mile = 5280 feet)] of rock formations, more geological history than is displayed anywhere else in the world. From the Paleozoic era rims to the bottom of the Precambrian era Inner Canyon, nearly two billion years of geological history are exposed. 

During the last million years, the Colorado River has cut its course through the Canyon's walls and has exposed a fossil record of the earth that dates to the first living organisms--sea life imprinted in rock that resemble jelly-fish. As succeeding layers of rock formations progress up the Canyon walls, fossils imbedded within tell the story of the changes in the earth since its beginning. 

The 1900 square miles of Grand Canyon National Park, and the 130,000 square miles of the Colorado Plateau in which it resides, are the most unique of the thirty-four natural regions comprising the United States. In this region, extensive areas of horizontal strata of sedimentary rocks, which have been exposed by the Colorado River and layered on top of one another, share the plateau with igneous rocks from volcanoes, cinder cones and lava flows. Structural upheavals created striking topographic features and the high base altitude of the Colorado Plateau. The plateau's general surface area has an elevation of more higher than 5000 feet and some subplateaus, and several peaks at the nearby San Francisco Peaks, reach up to 11,000 feet. This uplifting, coupled with the brightly colored and highly varied scenery, make the region one of the most unusual places in the world. 

Source: Grand Canyon: A Natural Wonder of the World., Steven L Walker, Camelback/Canyonlands 1991
             Contact: 8655 East Via de Ventura, Suite G200
                      Scottsdale, AZ 85258 
                      Tel: 800-283-1983. 

                      ISBN: 1-879924-01-3